The formal definition, according to Wikipedia, is "an expression consisting of variables and coefficients which only employs the operations of addition, subtraction, multiplication, and non-negative integer exponents."

Ok, that probably didn't help, did it? What does it really mean? Well, a polynomial is something that looks like this:

It contains variables ($x$), it uses multiplication, subtraction, and addition, and has a positive, integer exponent (the $x^2$ term).

Polynomial Lessons

• Adding and Subtracting Rational Functions
• Combining Like Terms
• Multiplying Polynomials
• Polynomials: Definitions / Evaluation
• Polynomial (from MathWorld)